Cold cathode discharge display apparatus manifesting memory action

ABSTRACT

In a cold cathode display apparatus of the class comprising a plurality of opposed electrodes and a transparent envelope containing the electrodes and filled with a luminous inert gas, there are provided a plurality of display units in the envelope. Each display unit comprises a plurality of first electrodes, a plurality of second electrodes, insulator spacer means disposed between the first and second electrodes, the spacer means being provided with a plurality of perforations which define independent discharge cells between the first and second electrodes, a plurality of starting anode electrodes respectively contained in the discharge cells, a plurality of starting cathode electrodes respectively contained in the discharge cells, a plurality of resistors respectively connected to the second electrodes and a plurality of erasing electrodes disposed near the first electrodes. The plurality of display units are arranged in the direction of lines, the erasing electrodes of respective display units are arranged in the direction of lines, and the first electrodes and the starting anode electrodes of respective display units are arranged in the direction of columns. The starting cathode electrodes and the second electrodes of respective display units are arranged in the direction of both lines and columns.

United States Patent 11 1 Sasaki et al.

[ COLD CATHODE DISCHARGE DISPLAY APPARATUS MANIFESTING MEMORY ACTION[75] Inventors: Rentaro Sasaki; Akinori Watanabe,

both of Takasaki; Tatsuo Ogasawara, Tokyo; Satoshi Watanabe; HidetoshiSogabe, both of Gyoda, all of Japan [73] Assignee: Oki Electric IndustryCompany Ltd Minato-ku, Tokyo, Japan [22] Filed: Sept. 29, 1972 [21]Appl. No.: 293,574

[30] Foreign Application Priority Data Sept. 30, 197! Japan 46-76702 [52us. Cl. 313/217, 313 220 [51] Int. Cl. l-l0lj 61/06 [58] Field of Search313/2l7, 220

[56] References Cited UNITED STATES PATENTS 3,509,408 4/1970 Holz313/220 Primary Examiner-Roy Lake Assistant Examiner--Darwin R.Hostetter Attorney-C. Yardley Chittick et al.

suture 10M 1451 Jan.8,1974

1571 ABSTRACT In a cold cathode display apparatus of the classcomprising a plurality of opposed electrodes and a transparent envelopecontaining the electrodes and filled with a luminous inert gas, thereare provided a plurality of display units in the envelope. Each displayunit comprises a plurality of first electrodes, a plurality of secondelectrodes, insulator spacer means disposed between the first and secondelectrodes, the spacer means being provided with'a plurality ofperforations which define independent discharge cells between the firstand second electrodes, a plurality of starting anode electrodesrespectively contained in the discharge cells, a plurality of startingcathode electrodes respectively contained in the discharge cells, aplurality of resistors respectively connected to the second electrodesand a plurality of erasing electrodes disposed near the firstelectrodes. The plurality of display units are arranged in the directionof lines, the erasing electrodes of respective display units arearranged in the direction of lines, and the first electrodes and thestarting anode electrodes of respective display units are arranged inthe direction of columns. The starting cathode electrodes and the secondelectrodes of respective display units are arranged in the direction ofboth lines and columns.

5 Claims, 4 Drawing Figures Pmmcm 3 m4 3. 784.864

SHEET 10F 3 ERASING ANUDE STARTING BATHODE BATHUDE SUBSTRATA 1 COLDCATI'IODE DISCHARGE DISPLAY APPARATUS MANIFESTING-MEMORY ACTIONBACKGROUND OF THE INVENTION This invention'r'elates to an improved coldcathode dischargedisplay apparatus, and more particularly to coldcathode discharge display apparatus manifesting memory action andcapable of erasing and rewriting a pattern at any desired position.

I apparatus sold under the trade marks Elfin and Planitron a pluralityof display units each consisting of a plurality of segment electrodes,and a counter electrode disposed to oppose the segment electrodes with apredetermined spacingtherebetween, are disposed side by side in the sameenvelope. Such display apparatus is used to display patternsof aplurality of digits by selectively operating the display units on thetime division basis at such a high speed that does not cause flickering.

However, such a display apparatus lacks memory function so that it isnecessary to provide an independent memory device thereby increasing thecost of manufacturing and complicating the construction of the displayapparatus.

Although a memory action can be provided for the display apparatus byutilizing plasma luminescence, the plasma luminescence requires a highvoltage high frequency AC source operatingat a voltage of 200 V and at afrequency of 200 KHz. Moreover in such display apparatus it isimpossible to erase a desired memory.

SUMMARY OF THE INVENTION Accordingly, it is an object of this inventionis to provide an improved cold cathode discharge display apparatus ofcompact construction and capable of manifesting memory function withoutproviding an independent external memory device.

A further object of this invention is to provide an improved coldcathode discharge, display apparatus capable of erasing and rewriting apattern at any desired position.

According to this invention there is provided a cold cathode dischargedisplay apparatus of the class comprising a plurality of opposedelectrodes and an envelope containing said electrodes and filled with aIuminous inert gas, at least a portion of the envelope beingtransparent, characterized in that there are provided a plurality ofdisplay units in the envelope, that each of the display units comprisesa plurality of first electrodes, a plurality of second electrodes,insulative spacer means disposed between the first and secondelectrodes, the spacer means being provided with a plurality ofperforations which define independent discharge cells between the firstand second electrodes, a plurality of starting anode electrodesrespectively contained in the discharge cells, a plurality of startingcathode electrodes respectively contained in the discharge cells, aplurality of resistors connected to the second electrodes, and aplurality of erasing electrodes disposed near the first-electrodes, thatthe plurality of display units are arranged in the direction of lines,that the erasing electrodes of respective display units are arranged inthe direction of lines, that the first electrode and the starting anodeelectrodes of respective display units are arranged in the direction ofcolumns and that the starting cathode electrodes and the secondelectrodes of respective display units are arranged in the direction ofboth lines and columns.

BRIEF DESCRIPTION OF THE DRAWINGS The invention can be more fullyunderstood from the following. detailed description taken in conjunctionwith the accompanying drawings in which:

FIG. 1 shows an exploded perspective view of the various componentelements ofa cold cathode discharge display apparatus constructedaccording to the teaching of the invention;

FIG. 2 is a plan view showing the starting cathode substrate utilized inthe display apparatus shown in FIG. 1;

FIG. 3 shows an enlarged sectional view of the cathode substrateemployed in the display apparatus shown in FIG. 1 and FIG. 4 shows anequivalent circuit of the cold cathode discharge display apparatus shownin FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring not to FIG. 1 of theaccompanying drawings, a cold cathode discharge display apparatus 1shown therein comprises upper and lower substrates 2 and 3 made oftransparent material such as glass and forming a portion of the envelopewhich is formed in a manner to be described later. Between the upper andlower substrates are disposed a plurality of parallel erasing anodes 4athrough 4d, one for each line, a plurality of parallel anode electrodes50 through 5d, one for each column, a plurality of parallel startinganodes 6a through 6d, also one for each column, a starting cathode plate7, and a cathode substrate 8. Insulator spacers 9 through 12 areinterposed respectively between erasing anodes and anode electrodes,between anode electrodes and starting anodes, between the starting anodeand the starting cathode plate and between the starting cathode plateand the cathode substrate. Each of the electrodes and. spacersinterposed between the upper and lower transparent substrates 2 and 3are provided with a plurality of groups of perforations 13 which arearranged in aligned matrixes. The inner walls of the perforations of thestarting cathode plate 7 are provided with through hole platings, eachacting as a starting cathode electrode 14. Alternate starting cathodeelectrodes 14 on each line are connected to terminals 15 on the oppositeends of the plate 7, as shown in FIG. 2.

As shown in FIG. 3, the cathode substrate 8 comprises a sheet ofinsulator provided with a plurality of groups of perforations 13 whichare arranged in matrixes and solid state resistors 16 formed bycompressing a powder of glass or ceramic are contained in respectiveperforations 13. The upper surfaces of the resistors l6 confronting theanode electrodes 5a through 5d are coated with electrodes 17 which areformed by plating nickel, for example, whereas the lower surfaces of theresistors 16 are electrically connected to a thin conductive sheet 18having substantially the same coefficient of thermal expansion as thelower substrate 3 made of glass or ceramic, the thin sheet 18 serving asa common lead wire for the resistors 16.

Various electrodes and spacers described above are superposed one uponthe other between the upper and lower transparent substrates 2 and 3 toform a lamination and the periphery of the lamination is sealedhermetically with frit glass or the like to form an envelope. Afterevacuation, the interior of the envelope is filled with a luminous inertgas such as argon gas or neon gas thereby completing a cold cathodedischarge display apparatus with four lines and four columns. As shownin FIG. 1, erasing anodes 4a 4d, anode electrodes 5a 5d and startinganode electrodes 6a 6d are provided with terminals 19a l9d, 20a 20d and21a 21d, respectively, extending through the side walls of the envelopedformed as above described.

FIG. 4 shows an equivalent circuit for four columns and two lines of thecold cathode discharge display apparatus described hereinabove. In FIG.4, the component elements corresponding to those shown in FIG. 1 aredesignated by the same reference numerals. There are also provideddriving members 22a and 22b for starting cathodes, protective resistors230 through 23n and 24n through 24n for limiting the current flowingthrough the starting cathodes, input terminals 25a and 25b for drivingmembers 22a and 2212, respectively.

The first and second lines are designated by H, and H and the first tofourth columns by V, through V.,, respectively. The relative spacingsbetween anode electrodes 5a 5d, starting anode electrodes 6a 6d,starting cathode electrode 14 and cathode electrode 17 are selected tosatisfy the following conditions:

A. The breakdown or discharge initiating voltage between the anode andcathode electrode is higher than the breakdown voltage between thestarting anode and the starting cathode and the breakdown voltagebetween the anode and the cathode electrode when a discharge is beingmaintained between the starting anode and the starting cathode is lowerthan the voltage impressed across the anode and cathode electrodes.

B. The discharge sustaining voltage between the starting anode and thestarting cathode electrode is higher than the discharge sustainingvoltage between the anode and cathode electrodes.

C. The voltage relations between the erasing anode and the cathodeelectrode are made to be substantially the same as those between theanode and cathode electrodes.

Typical values of these voltages are as follows:

Breakdown voltage between the anode and cathode electrode-200 VDischarge sustaining voltage between the anode and cathode electrodes130 V Breakdown voltage between the starting anode and the startingcathode- 190 V Discharge sustaining voltage between the starting anodeand the starting cathode-180 V In operation, a voltage lower than thebreakdown voltage 200 V is impressed across anode electrodes 5a 5 a andcathode electrode 14. More particularly, a voltage of +100 V isimpressed upon respective anode terminals a 20d whereas a voltage of S0V is impressed upon the cathode electrode. Upon application of an inputsignal upon input terminal a, the driving member 22a operates to selectan appropriate ones of the starting cathode electrodes 14a through 14acorresponding to the pattern information contained in the input signalwhereby a pulse signal of -50 V is applied to the selected startingcathode electrode through corresponding one of resistors 230 through23n. Concurrently therewith, a pulse signal of+l 50 V is impressed uponthe terminal 21a of the starting anode to increase the potentialdifference between the starting anode and the starting cathode to 200 Vwhich is higher than the breakdown voltage (l V) between theseelectrodes. As a result, an electric discharge is established between aselected starting cathode, for example, l4a, positioned at thecross-point between the first line H, and the first column V, andstarting anode 6a. Once the discharge is established between theselected starting anode and the starting cathode, the voltage dropbetween these electrodes decreases to a value lower than the voltage Vwhich has already been applied across corresponding anode electrode 5aand cathode electrode 17a so that the discharge will be automaticallytransferred to between these anode and cathode electrodes from betweenstarting anode 6a and starting cathode 14a.

In the same manner, when a voltage is impressed across input terminal25a, and terminal 21b for the starting anode, an electric discharge isestablished between a selected one of the starting cathodes 14a throughMn and the starting anode 6b and this discharge is transferred tobetween a selected one of the cathode electrodes 17a through 17n andanode electrode 5b thereby displaying the desired pattern at thecross-point between the first line H, and the second column V During theabove described operation, when a voltage is applied to a selected oneof the starting electrodes 14a through l4n, this voltage is also appliedto the starting cathode 14a through 14:1 of the other display units.However, since voltage is not being applied upon the starting anodeelectrodes of the other display units, only the desired display unitwherein a synchronized voltage has been applied across the selected oneof the starting anodes 6a through 6d and the starting cathodes 14athrough l4n displays the desired pattern and other display units are noteffected. For this reason, the pattern displayed in this manner will becontinuously displayed even after the termination of the input signalimpressed across the selected starting cathode and starting anode. Thismeans that the novel display apparatus has a memory action. In thismanner, all patterns are successively displayed. When the display of allpatterns is completed if there is any erroneous display in any displayunit, for example a display unit at the cross-point between the firstline H, and the second column V such an erroneous display can becorrected in the following manner.

First, a voltage equal to the-voltage that has been applied to theselected one of the anodes 5a through 5d is impressed upon erasing anode19b other than the erasing anode 19a which corresponds to the first lineon which the error has occurred. Then, the voltage is removed from theanode terminal 20b corresponding to the second column on which the errorhas occurred. Under these conditions, the voltages are removed from theerasing anode 4a and anode 5b of only the display unit corresponding tothe cross-point between the first line H, and the second folumn V In theother display units, however, since the voltage is being impressed uponthe erasing anode 191) or either one of the anode 5a, 5c and 5d, adischarge is sustained between an electrode impressed with this voltageand a cathode. By this operation it is possible to readily erase thepattern displayed at any desired display unit; To write again thepattern in the erased display unit, above described predeterminedvoltage is impressed across the starting anode 6b and the selected oneof the starting cathodes 14a through l4n.

Although in the illustrated embodiment the erasing anodes are disposedto the outisde of the anode electrodes, the exact position of theerasing anodes are immaterial provided that they are located close tothe anodes. Further, although a positive potential was applied to aplurality of electrodes which are arranged in a matrix to cause them tooperate as cathode electrodes and a positive potential was applied tothe electrodes in re spective display units to cause them to operate asanode electrodes, it should beunderstood that the polarities of thesepotentials may be reversed.

Thus, it will be clear that the invention provides a new and improvedcold cathode discharge display apparatus of compact construction capableof manifesting memory action, that is a display apparatus capably ofcontinuously displaying a pattern without using an expensive externalmemory device. Moreover, in the novel display apparatus it is possibleto readily erase any desired or erroneous pattern and rewrite it.

While the invention has been shown and described in terms of a preferredembodiment thereof, it should be understood that many changes andmodifications are obvious to one skilled in the art without departingfrom the true spirit and scope of the invention as defined in theappended claims.

What is claimed is:

l. A cold cathode discharge display apparatus manifesting memory actioncomprising a plurality of display units, each including a plurality offirst anode electrodes, a plurality of second cathode electrodes,insulative spacer means disposed between said first and secondelectrodes, said spacer means being provided with a plurality ofperforations which define independent discharge cells between said firstand second elec' trodes, a plurality of starting anode electrodesrespectively contained in said discharge cells, a plurality of startingcathode electrodes respectively contained in said discharge cells, aplurality of resistors respectively connected to said second electrodes,a plurality of erasing electrodes disposed near said first electrodes,and an envelope containing said plurality of display units, at least aportion of said envelope being transparent, said plurality of displayunits being arranged in the direction of lines, said erasing electrodesof respective display units being arranged in the direction of lines,said first electrodes and said starting electrodes of respective displayunits being arranged in the direction of columns, and said startingcathode electrodes and said second electrodes of respective displayunits being arranged in the directions of both lines and columns.

2. The display apparatus according to claim 1 wherein said erasinganodes, said first electrodes, said starting anodes, said startingcathodes and said second electrodes of each display units are providedwith a plurality of perforations respectively aligned with theperforations of said spacer means, said perforations being arranged in aplurality of matrixes.

3. The display apparatus .according to claim 1 wherein said spacer meanscomprises a plurality of perforated insulator sheets which arerespectively interposed between said erasing anode electrodes and saidfirst electrodes, between said first electrodes and said starting anodeelectrodes, between said starting anode electrodes and said startingcathodes electrodes, and between said starting cathode electrodes andsaid second electrodes and wherein the perforations of said plurality ofinsulator sheets are in alignment with those of said erasing anodeelectrodes, first electrodes, starting anode electrodes, startingcathode electrodes and said second electrodes. v

4. The display apparatus according to claim 1 wherein said secondelectrodes comprises an insulator sheet provided with a plurality ofperforations which are grouped into a plurality of matrixes, a pluralityof resistors contained in respective perforations, and thin metal layersapplied on one ends of said resistors.

5. The display apparatus according to claim 1 wherein said componentelements of each display units are superposed one upon the other betweena pair of transparent substrate to form a lamination and the peripheryof said lamination is hermetically sealed to form said laminations.

Rentaro Sasaki, AkinoriWatanabe, Tatsuo Ogasawara, IHVCMOTM) SatoshiWatanabe, Hidetosh'i Sogabe It is Certified that: error appears in Lhenbove-j h nteificed patent and that said LuLturs; laLcntareherebycorrvctml as; shown below:

In "[731 Assignee:-"after Oki Electric Industry Company Ltd.,

Minato-ku, Tokyo, Japan" add Okaya Electric Industry Company Ltd.',Shibuya-ku, Tokyo, Japan l Column 2, line 29 "not" should lge now Column4 line 63 "folumn" should be" column Column 6, claim 4 line 38, "ends"should be end Signed and sealed thie 24th day of December 1974 (SEAL)Attest:

- MCCOY M. GIBSON JR. C, MARSHALL DANN Attesting Officer Commissioner ofPatents

1. A cold cathode discharge display apparatus manifesting memory actioncomprising a plurality of display units, each including a plurality offirst anode electrodes, a plurality of second cathode electrodes,insulative spacer means disposed between said first and secondelectrodes, said spacer means being provided with a plurality ofperforations which define independent discharge cells between said firstand second electrodes, a plurality of starting anode electrodesrespectively contained in said discharge cells, a plurality of startingcathode electrodes respectively contained in said discharge cells, aplurality of resistors respectively connected to said second electrodes,a plurality of erasing electrodes disposed near said first electrodes,and an envelope containing said plurality of display units, at least aportion of said envelope being transparent, said plurality of displayunits being arranged in the direction of lines, said erasing electrodesof respective display units being arranged in the direction of lines,said first electrodes and said starting electrodes of respective displayunits being arranged in the direction of columns, and said startingcathode electrodes and said second electrodes of respective displayunits being arranged in the directions of both lines and columns.
 2. Thedisplay apparatus according to claim 1 wherein said erasing anodes, saidfirst electrodes, said starting anodes, said starting cathodes and saidsecond electrodes of each display units are provided with a plurality ofperforations respectively aligned with the perforations of said spacermeans, said perforations being arranged in a plurality of matrixes. 3.The display apparatus according to claim 1 wherein said spacer meanscomprises a plurality of perforated insulator sheets which arerespectively interposed between said erasing anode electrodes and saidfirst electrodes, between said first electrodes and said starting anodeelectrodes, between said starting anode electrodes and said startingcathodes electrodes, and between said starting cathode electrodes andsaid second electrodes and wherein the perforations of said plurality ofinsulator sheets are in alignment with those of said erasing anodeelectrodes, first electrodes, starting anode electrodes, startingcathode electrodes and said second electrodes.
 4. The display apparatusaccording to clAim 1 wherein said second electrodes comprises aninsulator sheet provided with a plurality of perforations which aregrouped into a plurality of matrixes, a plurality of resistors containedin respective perforations, and thin metal layers applied on one ends ofsaid resistors.
 5. The display apparatus according to claim 1 whereinsaid component elements of each display units are superposed one uponthe other between a pair of transparent substrate to form a laminationand the periphery of said lamination is hermetically sealed to form saidlaminations.